Sapsuckers and sap flow

What: Last week, I was out checking the bees with Zac and Sophia and we noticed that the boxelder looked like it had wet its pants. A few days earlier, Clay had spotted an odd ball woodpecker in our backyard and I thought from a quick glimpse it may have been a sapsucker. When we inspected the "wet spots" on the boxelder, sure enough there were all sorts of little drill holes. We licked the bark and it was delicious.



There are a lot of origin stories about the human discovery of maple sugaring. I'll bet almost all of them are false and created many generations after humans were utilizing syrup. I've got three bets for how humans discovered sugaring:

1. Red Squirrels: I've watched red squirrels chew little notches in branches of sugar and red maples. I've also watched them return and lick off the sap from bark later.
2. Sapsuckers: Water can be hard to come by in the winter. Curiosity, particulalry when there's a need for something, runs high in humans. My first inclination when I saw the drill holes and wet bark was to wonder what the sapsucker was after. My second inclination was to taste the sap. I was rewarded with a delicious treat.
3. Broken branches: Silver maples and boxelders both grow along floodplains. Winter can be rough on trees and without the metabolic activity to heal wounds, exposed wound sites will "bleed" once the sap starts flowing. Early in the sugaring season, when temperatures still drop well below freezing at night, any sap that might flow out of a broken branch can freeze into a sapsicle. The water freezes first and the outer coat is extra sweet. Kids love to suck on icicles and I'll be it was a kid that first discovered these sweet treats. 

I've kept an informal list over the years of species that I've seen sapsuckers tapping. The list this year includes: Black walnut, Red oak, Boxelder, Silver maple, Hemlock, Bitternut hickory, White pine, Norway spruce, Black cherry, and Paper birch.

black walnut with drill holes from sapsucker

Poppies

Cut stem of bloodroot oozing red sap

What: With all the bloodroot coming up in our woods, I got curious what other poppies we have here in Vermont. And it doesn't look like much. Magee and Ahles's Flora of the Northeast, which is a complete record of all vascular plants in NE and NY, lists 6 genera and 9 species. Only two of these are found in Vermont, bloodroot (Sanguinaria canadensis) and celandine poppy (Chelidonium majus). I posted about bloodroot last week. Celandine is an extremely abundant plant, at least in Burlington, growing in sandier, but moist waste places. It has beautiful yellow flowers and super furry stems/undersides of leaves. I've used the sap as a dye and got a yellowish-orange color.

Bloodroot rhizome cut in half to show showing "blood" beading up on surface

Ecological notes: I was mostly curious because things in the poppy family exude a milky sap that has a yellow/orange/red hue to it. The sap of poppies (family Papaveraceae) contains isoquinoline alkaloids, which are narcotics. These compounds are largely toxic to animals and have a fowl smell. Morphine comes from opium poppy (Papaver somnifera). I'm not sure exactly why the sap is pigmented, but it may serve as a visual warning to would-be-predators not to eat the plant, as any broken part of the plant will readily ooze the brightly colored sap.

Celandine leaf stem broken to show yellow sap

Discovering sap

Sapcicle on a broken boxelder twig

What: There are lots and lots of stories concerning the origins of sugaring. The stories have grown over many generations and may or may not resemble the original tellings of the story. As was pointed out to me by Judy Dow, basketmaker and member of Oyate, an organization that protects and preserves indigenous stories and culture, many of the stories white people tell about Indians sugaring have been bastardized, distorted, misappropriated, and anglicized. In their new forms, they now tell the stories of colonialization. They may not even reflect how sugaring was discovered in the first place or adequately/accurately portray the culture from which the story may have originated.

Websites for sugaring operations are quick to root the practice in indigenous folklore (whether it be the Abenaki story of Gluskape diluting sugar, the Haudenosaunee story of the chief sticking his hatchet in a tree, or another story of red squirrels chewing branches). I tend to be skeptical of the credibility of websites that generalize these stories and say things like, "The Indians made maple syrup. They would take a hatchet and cut a gash in the tree and insert a wooden or bark shim. The sap poured off into pots. The trees were bigger back then, and must have had plenty of sap. The Indians concentrated the sap by dropping hot rocks into the pot to boil off some of the water." Adding to my mistrust of these sources is that I'm always skeptical until I try something myself to prove (or disprove) it or observe it myself (like watching a red squirrel "tap" a sugar maple at Rock Point and come back later to eat the icicles and lick the wound sites).

Like most things, I'm sure there are elements of truth in all of the stories we've inherited about maple sugaring. My own sugaring origin story, if I didn't already know about sugaring might have begun last week when I started seeing all these rotting white pines laying on the forest floor in Centennial Woods. My attention was drawn to the down slope side, where almost all the stumps had icicles oozing out. The icicles were all a beautiful amber color with these dark hair-like strands curling up on the bottom. I tasted a few and they had an almost coffee-like flavor. They were okay, but not great. On my way back home, I spotted a boxelder that had been crushed by a careless UVM facilities truck, leaving many branches broken (see image at top). At the wound sites, icicles hung down. Each icicle had the sweetest droplet of sugar water beaded up at the tips.

I paddled the Winooski River with Brian on Saturday and at one point we paddled under a silver maple tree yawning over the gentle river. From some past flood event a few of the lowest branches had been broken off. The sap had been oozing out of the broken twigs and in the cold had formed icicles. Brian and I enjoyed sucking the sweet icicles off the branches. With such a sweet surprise, I'm sure any curious mind would have wondered what other trees would ooze a sweet sap and how could they harvest more of it. I'd start breaking branches, bending them over to collect in little containers. I don't know that I would rock boil them, but I'd drink nothing but sap water for the first month or two of spring when it was flowing in the maple genus. I'll bet harvesting sap from twigcicles would have come before "tapping" the trees, or harvesting in some other way from the bole, or trunk, of the tree.

Where: Broken branches everywhere

Other notes: Maples are still the only species to be flowing so far.

Beyond maple syrup

Spiles: (L to R) elderberry, sumac, late 1800s model, 1950s model

What: 3 years ago, one of my students told me about her family's sugaring operation in New York. While talking to her I realized I'd never had straight sap before. That semester, Bekah brought me a 20 oz bottle filled with the sweetest water I'd ever had. Wanting to tap my own trees, the following year I bought some spiles (the taps) and buckets. I don't have any sugar maples (Acer saccharum) in my backyard so I decided to try and eke some sweet syrup out of the trees I do have.

Embarassingly out of focus shot of the ESS group
carving their own sumac/elderberry spiles 

Yesterday, with the Earth Skills Seminar, we tapped 13 different species:

• Norway maple** (Acer platanoides)
• Boxelder (Acer negundo)
• Silver maple (Acer saccharinum)
• Red maple (Acer rubrum)
• White ash (Fraxinus americana)
• Apple (Malus domesticus)
• Big-toothed aspen (Populus grandidentata)
• Black cherry (Prunus serotina)
• Hackberry (Celtis occidentalis)
• Black locust** (Robinia pseudo-acacia)
• Smoke tree** (Cotinus sp.)
• Black walnut (nigra)
• Paper birch (Betula papyrifera) Zac thinks it's a gray birch, but we'll see.  

We're planning on tapping European larch (Larix decidua), red oak (Quercus rubra), staghorn sumac (Rhus typhina)**, and a buckthorn (Rhamnus cathartica)** as well.


** I would categorize all of these species as potentially disgusting to mildly toxic. Both smoke tree and staghorn sumac are in the cashew family (Anacardiaceae), and members of this family have sap that is purportedly toxic. So rather than attempt to make syrup out of the more toxic species, one of my hopes is to get a sense of when the different species have their sap flow relative to the other species. From here, I'd like to find correlations to different characteristics of each species (like habitat range, simple vs compound leaves, ring-porous vs diffuse porous, etc.).

I'll post results of our experiment as they emerge!

Also, I included Norway maple in this list even though the sap is perfectly edible. Trees get "buddy" by the end of the season as they shift from sending sugar/nutrients from the roots up to the twigs to producing chemical defenses. During the summer a broken Norway maple leaf stem will ooze a milky white sap, which tastes terrible. As the early spring sap flow progresses, the sap of Norway maple shifts to being murkier and fouler. I would assume that at this time they're ramping up defenses for the emergence of flying insects and other would-be predators.

Other notes: One thing we said at the Earth Skills Seminar today is that we won't talk about edible/medicinal things that we haven't ourselves tried. I read a lot of bogus stuff on the internet about different saps - a lot of people just citing other unreliable sources. What we hope to do here is take calculated risks to know for myself what is and what isn't a reliable source of sap each spring.